This application claims the priority of German application 197 20 518.6, filed May 16, 1997, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a transfer press for machining sheet metal parts, particularly a suction press, having at least one press station in which a bedplate is arranged which, as required, can be moved out of the press station and which is used for receiving at least one mold to be exchanged as required, for machining the sheet metal part, and a transfer device for feeding and/or removing the sheet metal parts to or from the press station in a defined transfer direction, the transfer device including at least one holding device to be changed when required for the temporary holding of the sheet metal parts which is situated in the transfer direction in front of and/or behind the mold when the mold is closed.
The present invention also relates to a process for the mold change and tooling change in such a transfer press having at least one bedplate on which at least one mold is held, and having a transfer device which has at least one holding device which can be changed as required.
Known transfer presses, as shown in EP-B-0 388 610, have a succession of press stations through which a workpiece has to travel in the transfer direction. The press stations are defined by molds divided into a top mold parts and a bottom mold part. The top mold part is fastened to a slide and the bottom mold part is disposed on a bedplate. A transfer device, for example, a two-axis transfer device with cross traverses, is used for the transport of the workpieces, on which cross traverses suction frames are held. In addition, the press has a press frame which includes press stands normally arranged between the working stations.
For the mold change, the bedplates with the molds disposed thereon are normally guided laterally out of the transfer press. They are moved through the press stands, the space conditions usually being such that the bedplates just fit through the press stands.
During the operation of the conventional transfer press, the suction frames or other holding devices pertaining to the transfer system are held between the molds, i.e., in the area for example, of the press stands when the molds close. The holding devices must first also take up this position if the top mold part is deposited on the bottom mold part in order to be able to move it out of the transfer press by way of the sliding table.
In addition to the mold change, the holding devices must also be changed. This should naturally take place in a manner which is as simple and requires expenditures of personnel which are as low as possible. At least some holding devices cannot, however, simply be guided laterally out of the transfer press because they would otherwise collide with the press stands.
Accordingly, an object of the invention is to provide a transfer press which permits a simple mold change including a simple tooling change, in which the tooling also includes holding devices which are part of a transfer system.
This object has been achieved in accordance with the present invention by providing a transfer press wherein at least one receiving device for the holding device is provided on the bedplate and/or the mold, and the receiving device holds the holding device during the mold change in a depositing area with an orientation which differs from the orientation of the holding device in the operating position. The process for changing the mold and the tooling involves steps wherein the holding device is swivelled out of its operative position into a changing position in which the holding device is held with respect to the transfer direction laterally next to the mold on a corresponding receiving device and in that the bedplate with the mold and the holding device (tooling) is moved out of the transfer press.
The transfer press of the present invention has a receiving device which has the purpose of depositing the tooling removed from the transfer system on the bedplate (or the mold) so that the bedplate with the mold and the tooling can be moved out of the transfer press.
According to the present invention, the tooling is held on the receiving device in an orientation and alignment which differs from the orientation in the transfer system. Thereby, for example, holding devices of the transfer system related to the tooling are deposited at a point on the bedplate at which, particularly with respect to the transfer direction, they do not project beyond the table contour.
A correspondingly provided transport device for the tooling is capable of changing the spatial orientation of the holding devices corresponding to the purpose so that the holding devices can be deposited at points on the bedplate which cannot be reached by the transfer system alone. Thereby, the holding devices are deposited at the otherwise not utilized points of the mold or the bedplate at which they do not hinder the moving-in and moving-out of the bedplate from the transfer press. In addition, the depositing points (receiving devices) may be selected such that the molds disposed on the bedplate are easily accessible, for example, to a crane.
If, as the result of the construction of the transfer press according to the present invention, on the side of the bedplate situated in the front and the rear in the transfer direction, additional space is not required for the holding devices (the tooling), the bed plates can be set up spaced from one another by only the with of a press stand. The distances between the bedplates and thus between the molds therefore become very short and permits a fast workpiece transfer and thus a high timing rate of the press.
The transport device for changing the tooling from the transfer system into the depositing area of the bedplates is advantageous particularly in transfer presses with two-axis transfers. The holding devices held on the cross traverses, for example, suction frames, suction spiders or the like, require a relatively large amount of space. In this case, the transport device permits the depositing at neutral points of the bedplate or of the mold. While the suction frames extend with the cross traverses in the operative position transversely to the transfer direction, they are deposited in the inoperative position in the longitudinal direction laterally to the molds. This is an area which is not crossed during the sheet metal part transport by the respective sheet metal part. Thereby, the transfer press can be constructed as short as possible in the transfer direction which benefits the stroke number.
The holding device can be held being oriented in the lateral area of the bedplate in the longitudinal direction as well as vertically. This depends on the concrete construction of the receiving device. The transport device correspondingly has a vertical, a horizontal or a diagonally arranged swivel axis. The transport device may be arranged on the bedplate or the mold and may, at the same time, be used as a receiving device for the holding system of the holding device in the inoperative position. The transport device can, however, also be arranged as a transfer device and be held on a press stand, that is, separately of the bedplate, in the holding device is transferred to the holder provided at the bedplate.
As required, particularly in the case of bedplates which have several molds disposed at a distance from one another, individual holding devices (tooling) may be deposited between the molds. This applies particularly to holding devices which, in the inoperative position are held above the bedplate between the molds and thus not in the area of press stands. These holding devices are not swivelled during the depositing on the bedplate.
The transfer device can be constructed such that the taken-over holding device is swivelled through the open mold or over the closed mold detached from the slide. The latter may be expedient if the transfer device carries out not only a swivel movement but simultaneously also a lifting movement, or if the depositing on the bedplate takes place relatively high.
According to the present invention, during the mold and tooling change, the tooling, which is part of the transfer system, is swivelled from its working position into a changing or inoperative position and is deposited on the bedplate. The bedplate, which is preferably constructed as a sliding table, is then moved out of the transfer press together with the mold and the tooling. By way of swivelling of the tooling, particularly of the holding devices, they can be transported to the lateral areas of the bedplate. Therefore, for depositing the holding device, no additional space needs to be provided which extends the bedplate in the transfer direction. In the lateral area, the holding device can be held horizontally or vertically, but at least in a plane which is aligned vertically and in the longitudinal direction. The holding device, which is, for example, constructed as a suction frame or a suction spider, can be held in a flat manner as well as may be held to be rotated about its longitudinal axis. For this purpose, the transport device has at least two swivelling or rotating axes.